There has been a recent rise in the disease burden of inflammatory bowel disease (IBD) in India and other Asian countries and as per a recent report, the overall number of IBD patients in India is second highest in the world after USA [
This study was therefore planned to compare body composition between patients of UC and CD, correlate body composition with disease severity and duration in both UC and CD patients, correlate body composition with disease behavior in CD and disease extent in UC, and correlate abdominal fat with disease behavior, severity, and disease duration in CD patients.
Adult patients with diagnosis of ulcerative colitis and Crohn’s disease attending the inflammatory bowel diseases (IBD) clinic at All India Institute of Medical Sciences, New Delhi, India, from Dec 2014 to Dec 2015, were screened for inclusion in the study. Of these, patients who consented for bioimpedance analysis were included in the study. Written informed consent was obtained from all patients included in the study. Institutional ethics committee approved the study.
In this prospective study, patients with UC and CD were subjected to a uniform clinical evaluation including detailed history and examination, laboratory assessment, endoscopy (UGI endoscopy or colonoscopy as appropriate), and mucosal biopsies. Patient data was collected on their demographics, clinical, endoscopic, histologic, and radiologic features and treatment given and its response. All patients underwent body fat measurement with the bioimpedance machine. In addition, visceral fat area, subcutaneous fat area, and visceral to subcutaneous fat ratio (VF/SC) was evaluated in patients with Crohn’s disease with the help of abdominal CT.
The patients were diagnosed as CD on the basis of the European Crohn’s and Colitis Organization (ECCO) guidelines, with a combination of clinical, endoscopic, and histological features [
Diagnosis of ulcerative colitis was made on the basis of European Crohn’s and Colitis Organization (ECCO) guidelines with a combination of clinical symptoms like bloody diarrhoea and endoscopic appearance and histological findings compatible with ulcerative colitis [
Total body fat was measured by leg to leg bioimpedance machine (TANITA body composition analyzer, model TBF-215) in patients of ulcerative colitis and Crohn’s disease [
Lean mass was calculated with the following formula: Lean mass = Body weight
Fat-free mass index (FFMI) was calculated with the following formula: FFMI = (Lean mass/2.2)/((Height in meters)2 × 2.20462).
Visceral fat (VF) and subcutaneous fat (SC) area were measured at the level of umbilicus (L4 vertebrae level) with the patient in supine position by multislice CT scanner (Siemens, Erlangen, Germany) in all the patients. The technique used for fat tissue measurements on CT has been standardized and validated [
Qualitative data was expressed as frequency and percentage. Quantitative data was expressed as mean ± SD if normally distributed and as median (interquartile range) when the data distribution was skewed. BMI, fat percentage, fat mass, lean mass, and FFMI were compared between CD and UC by Student’s
A total of 53 patients with ulcerative colitis and 44 patients with Crohn’s disease were enrolled in the study (Table
Baseline characteristics of patients of ulcerative colitis and Crohn’s disease.
UC |
CD |
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Age in years, mean ± SD | 33.2 ± 11.2 | 41.2 ± 15.8 | 0.01 |
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Sex, male ( |
36 (67.9%) | 32 (72.7%) | 0.61 |
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Duration of symptoms (months), median | 24 (12–48) | 36 (18–105) | 0.15 |
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Haemoglobin, g/dL, mean ± SD | 11.8 ± 2.5 | 10.8 ± 2.9 | 0.02 |
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Albumin, g/dL, mean ± SD | 4.2 ± 0.5 | 4.0 ± 0.8 | 0.11 |
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Extent/location of disease | E1: 3 (5.6%) |
L1: 21 (47.7%) | |
L2: 10 (22.7%) | |||
L3: 11 (25%) | |||
L4: 10 (22.7%) | |||
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Disease behavior | B1: 21 (45.7%) | ||
B2: 23 (50%) | |||
B3: 2 (4.3%) | |||
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5-ASA | 53 (100) | 10 (22.7) | |
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Steroids | 16 (30.2) | 29 (65.9) | |
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Immunomodulators | 17 (32.1) | 26 (40.9) | |
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Biologics | 0 (0) | 0 (0) |
E1: proctitis; E2: left sided colitis; E3: pancolitis; L1: terminal ileum ± caecum; L2: colonic; L3: ileocolonic; L4: proximal small intestine; B1: inflammatory; B2: stricturing; B3: penetrating; p: perianal; ASA: aminosalicylic acid.
There was no significant difference in the mean BMI, fat percentage, and fat mass between CD and UC patients (Table
Comparison of body composition between patients of Crohn’s disease and ulcerative colitis.
Parameters | UC |
CD |
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Body mass index (kg/m2), mean ± SD | 21.1 ± 4.2 | 20.5 ± 3.7 | 0.51 |
Fat percentage, mean ± SD | 14.4 ± 9.1 | 15.6 ± 9.3 | 0.52 |
Fat mass in kg, mean ± SD | 9.04 ± 7.5 | 8.7 ± 5.9 | 0.81 |
Lean mass in kg, mean ± SD | 48.3 ± 8.4 | 44.2 ± 7.8 | 0.01 |
Fat-free mass index (FFMI), mean ± SD | 17.7 ± 1.9 | 17.2 ± 1.8 | 0.09 |
There was no effect of disease extent on any of the parameters (BMI, fat percentage, fat mass, lean mass, FFMI) (Table
Effect of disease extent, clinical and endoscopic severity, steroid requirement, and disease duration on body fat and lean mass in patients with ulcerative colitis.
BMI | Fat percentage | Fat mass in kg | Lean mass in kg | FFMI | |
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E1 |
21.9 ± 4.5 | 14.6 ± 9.5 | 9.4 ± 6.9 | 48.6 ± 8.4 | 18.5 ± 2.1 |
E2 |
21.3 ± 4.5 | 15.1 ± 10.1 | 9.6 ± 8.3 | 47.3 ± 8.3 | 17.8 ± 2.1 |
E3 |
20.2 ± 3.3 | 12.8 ± 6.4 | 7.4 ± 5.1 | 48.3 ± 8.4 | 17.5 ± 1.7 |
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0.64 | 0.73 | 0.44 | 0.77 | 0.72 |
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Remission |
22.1 ± 4.9 | 16.5 ± 10.2 | 10.9 ± 8.9 | 49.4 ± 9.3 | 18.1 ± 2.2 |
Mild |
20.2 ± 3.2 | 13.9 ± 8.6 | 8.1 ± 5.9 | 46.5 ± 7.3 | 17.2 ± 1.9 |
Moderate to severe |
19.9 ± 3.2 | 9.7 ± 4.9 | 5.7 ± 3.6 | 48.6 ± 7.8 | 17.9 ± 1.9 |
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0.23 | 0.13 | 0.14 | 0.54 | 0.36 |
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Grade I |
24.2 ± 5.3 | 22.6 ± 11.4 | 16.3 ± 10.8 | 51.9 ± 8.2 | 18.3 ± 1.6 |
Grade II |
20.3 ± 3.8 | 12.3 ± 7.9 | 7.4 ± 5.9 | 47.6 ± 8.5 | 17.6 ± 2.1 |
Grade III |
20.8 ± 3 | 14.7 ± 5.8 | 8.3 ± 3.7 | 47.7 ± 7.9 | 17.7 ± 1.9 |
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0.04 | 0.01 | 0.004 | 0.37 | 0.62 |
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None |
22.1 ± 5.3 | 16.7 ± 10.9 | 11.1 ± 10.1 | 48.1 ± 9.4 | 17.9 ± 2.0 |
1/year |
20.8 ± 3.6 | 12.8 ± 7.1 | 7.5 ± 4.6 | 48.9 ± 8.1 | 18.0 ± 1.9 |
>1/year |
20.6 ± 3.9 | 14.1 ± 9.2 | 8.8 ± 7.1 | 48.1 ± 8.2 | 17.5 ± 1.9 |
0.59 | 0.50 | 0.41 | 0.95 | 0.62 | |
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<1 year |
21.4 ± 2.9 | 14.5 ± 6.1 | 8.5 ± 4.5 | 47.6 ± 9.3 | 18.1 ± 1.7 |
1–5 years |
21.9 ± 4.8 | 15.8 ± 10.6 | 10.5 ± 8.9 | 49.4 ± 8.6 | 18.0 ± 2.0 |
>5 years |
17.9 ± 2.3 | 9.4 ± 6.0 | 4.9 ± 3.3 | 45.8 ± 5.5 | 16.1 ± 1.2 |
0.04 | 0.18 | 0.13 | 0.51 | 0.03 |
E1: proctitis; E2: left sided colitis; E3: pancolitis; Remission: SCCAI < 3; Mild: SCCAI 3–6; Moderate to severe: SCCAI > 6.
Of 53 patients, 26 were in clinical remission, 17 had mild disease activity, and 10 had moderate to severe disease activity. There was progressive, though not statistically significant, decline in BMI (
Of 53 patients, 7 patients had grade I, 37 had grade II, and 7 patients had grade III disease as per Baron’s endoscopic severity. Patients having grade II and III disease had significantly lower BMI (
There was no effect of steroid requirement on any of the parameters (BMI, fat percentage, fat mass, lean mass, FFMI) (Table
Among 53 patients, 14 had a disease duration of <1 year, 30 had a disease duration between 1 and 5 years, and 9 patients had disease duration > 5 years. The BMI (
There was no effect of disease behavior on any of the parameters (BMI, fat percentage, fat mass, lean mass, FFMI) (Table
Effect of disease behavior, clinical severity, and disease duration on body composition in patients with Crohn’s disease.
BMI | Fat percentage | Fat mass in kg | Lean mass in kg | FFMI | |
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B1 |
20.6 ± 4.4 | 14.8 ± 9.7 | 8.5 ± 6.9 | 43.8 ± 8.3 | 17.2 ± 2.0 |
B2 and B3 ( |
20.5 ± 2.9 | 16.4 ± 9.1 | 9.1 ± 5.1 | 44.4 ± 7.7 | 16.9 ± 1.7 |
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0.82 | 0.54 | 0.69 | 0.79 | 0.91 |
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Remission |
22.1 ± 4.2 | 18.3 ± 10.0 | 11.2 ± 7.0 | 46.4 ± 7.9 | 17.7 ± 1.9 |
Mild |
19.9 ± 2.3 | 15.6 ± 8.5 | 7.9 ± 4.4 | 41.8 ± 5.7 | 16.7 ± 1.2 |
Moderate to severe |
19.7 ± 4.2 | 12.9 ± 9.4 | 7.2 ± 5.9 | 44.6 ± 9.4 | 16.9 ± 2.3 |
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0.18 | 0.32 | 0.16 | 0.27 | 0.31 |
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<1 year |
22.5 ± 5.2 | 15.6 ± 8.6 | 10.9 ± 7.6 | 52.3 ± 8.3 | 18.6 ± 2.6 |
1–5 years |
19.4 ± 3.3 | 15.1 ± 10.0 | 7.8 ± 5.8 | 40.9 ± 6.5 | 16.3 ± 1.4 |
>5 years |
20.8 ± 2.5 | 16.2 ± 9.4 | 8.6 ± 5.1 | 43.6 ± 5.7 | 17.3 ± 0.9 |
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0.11 | 0.95 | 0.44 | 0.001 | 0.003 |
B1: inflammatory; B2: stricturing; B3: penetrating; Remission: CDAI < 150; Mild: CDAI: 150–220; Moderate to severe: CDAI > 220.
Of 44 patients, 14 were in clinical remission, 16 had mild disease activity, and 14 had moderate to severe disease activity. Like patients with UC, there was progressive, though not statistically significant, decline in BMI (
Among 44 patients, 9 had a disease duration of <1 year, 20 had a disease duration between 1 and 5 years, and 15 patients had disease duration > 5 years. The lean mass (
There was no difference in visceral and subcutaneous fat area and VF/SC ratio between patients with inflammatory disease versus patients with stricturing/penetrating disease phenotype (Table
Effect of disease behavior, clinical severity, and disease duration on visceral and subcutaneous fat area and visceral to subcutaneous fat ratio (VF/SC).
Visceral fat area | Subcutaneous fat area | VF/SC ratio | |
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B1 |
93.1 ± 59.2 | 105.8 ± 79.5 | 1.32 ± 0.8 |
B2 and B3 ( |
114.9 ± 79.2 | 108.4 ± 68.1 | 1.28 ± 0.7 |
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0.31 | 0.91 | 0.90 |
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Remission |
115.1 ± 54.1 | 141.04 ± 77.9 | 0.98 ± 0.4 |
Mild |
97.6 ± 54.9 | 95.9 ± 58.5 | 1.37 ± 0.6 |
Moderate to severe |
101.8 ± 99.2 | 86.2 ± 75.5 | 1.53 ± 0.9 |
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0.79 | 0.10 | 0.09 |
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<1 year |
106.5 ± 60.8 | 145.3 ± 88.2 | 1.09 ± 0.5 |
1–5 years |
93.6 ± 84.6 | 88.4 ± 62.8 | 1.36 ± 0.8 |
>5 years |
117.8 ± 55.4 | 109.4 ± 71.3 | 1.33 ± 0.6 |
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0.61 | 0.15 | 0.63 |
B1: inflammatory; B2: stricturing; B3: penetrating; Remission: CDAI < 150; Mild: CDAI: 150–220; Moderate to severe: CDAI > 220.
There was a statistically nonsignificant trend towards decline in subcutaneous fat area (
Like the fat mass, the subcutaneous fat area (
Among 27 patients of UC with active disease, 6 had a disease duration of <1 year, 18 had a disease duration between 1 and 5 years, and 3 patients had disease duration > 5 years. Like all patients, the effect of disease duration on BMI, fat percentage, fat mass, and FFMI showed similar trends, although the difference was not significant because of small numbers (Table
Effect of disease duration on body composition in patients of ulcerative colitis (UC) and Crohn’s disease (CD) with active disease (excluding patients in remission).
Disease duration (years) | BMI | Fat percentage | Fat mass in kg | Lean mass in kg | FFMI |
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<1 year |
20.9 ± 2.8 | 13.9 ± 6.7 | 7.6 ± 4.3 | 45.0 ± 6.5 | 17.4 ± 1.1 |
1–5 years |
20.3 ± 3.2 | 12.8 ± 8.1 | 7.7 ± 5.7 | 47.6 ± 8.1 | 16.9 ± 1.8 |
>5 years |
17.1 ± 2.2 | 6.1 ± 3.9 | 3.4 ± 2.7 | 49.5 ± 5.2 | 15.5 ± 1.3 |
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0.19 | 0.31 | 0.43 | 0.67 | 0.28 |
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<1 year |
20.8 ± 5.6 | 11.4 ± 8.6 | 7.7 ± 7.6 | 50.7 ± 8.4 | 17.6 ± 2.7 |
1–5 years |
19.4 ± 2.8 | 15.6 ± 9.2 | 7.8 ± 4.9 | 40.5 ± 7.0 | 15.7 ± 1.4 |
>5 years |
20.2 ± 2.5 | 13.5 ± 8.9 | 7.0 ± 4.6 | 44.0 ± 5.6 | 16.8 ± 1.0 |
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0.65 | 0.62 | 0.95 | 0.03 | 0.05 |
Among 30 patients of CD with active disease, 5 had a disease duration of <1 year, 17 had a disease duration between 1 and 5 years, and 8 patients had disease duration > 5 years. Like all patients, the effect of disease duration on lean mass and FFMI showed similar trends (
The present study highlights three major findings: low lean mass and fat-free mass in patients with CD as compared to UC; progressive decline in body fat with increasing disease severity both in UC (clinical as well as endoscopic) and CD (clinical) patients; and decline in fat-free mass with increasing disease duration, again in both UC and CD patients. There was no effect on body composition of disease extent in UC, and disease behavior in CD patients. The main purpose of body composition estimation in these patients is to determine existing differences and set nutritional and therapeutic goals for patients accordingly.
Lower lean mass in CD patients reflects worse nutritional status in CD than UC patients, which could be due to pan-intestinal and transmural involvement in CD resulting in poor oral intake and malabsorption. This finding is consistent with other recent studies from Poland [
Correlation of body composition with disease severity has not been well studied, and the results have been inconsistent across literature. In a previous study done from our center, like the present study, the fat mass in patients with active CD was lower than that of patients in remission, whereas there was no difference in the fat-free mass between active CD patients and patients in remission in both the studies [
The effect of disease duration on body composition was apparent in both UC and CD patients, but the trend was different. Among patients with UC, the effect of disease duration was seen only after 5 years, as BMI, FFMI, fat mass, and fat percentage were lower only in patients with disease duration > 5 years, whereas, among patients with CD, this effect was seen after 1 year only (lean mass, FFMI, BMI, and fat mass were lower in patients with disease duration > 1 year) indicating that malnutrition sets in early in the disease course of CD as compared to UC, and this can again be explained by the systemic nature of CD. The muscle active cytokines may stimulate protein degradation and inhibit myogenic differentiation and induce myoblast apoptosis, thereby leading to poor lean mass [
Visceral fat has been linked to pathogenesis of CD and studies have linked visceral fat with complicated disease behavior [
Our study has many limitations. The sample size was small and this could explain nonsignificant trend with many associations, because of type II error. Increasing the sample size could have led to more definite conclusions. We did not include healthy controls in our study, but multiple studies including a previous study from our center have already compared body composition in patients with IBD and controls, so comparison with controls would not have added to the results. Comparison of body composition in the same patients at different stages of endoscopic/clinical activity and at different time points (with respect to disease duration) would also have given better results.
To conclude, Crohn’s disease patients are at a higher risk of malnutrition than ulcerative colitis patients, there is a loss of fat mass with increasing disease activity in IBD patients, and their nutritional status deteriorates with increasing disease duration (earlier in CD). Therefore, proper assessment of nutritional status along with proper measures to improve these deficiencies is very important to improve the quality of life in patients with IBD.
The authors declare that there are no conflicts of interest regarding the publication of this paper.